Electric relay



NOV. 17, 1936.r 4 H, L COE 2,061,347

ELECTRIC RELAY Filed DeC. 8, 1934 lweidot'; HERBERT LEO/v COE,

/7/5 ifa/Waff.

Patented Nov. 17, 1936 UNITED. STATES PATENT GFFICE 3 Claims.

This invention is an electric relay that is se lectively responsive togrounding of either of two electric power lines.

An example of the relay is illustrated by the accompanying drawing,Figure 1 being a purely diagrammatic representation while Figure 2 goesmore into the mechanical details.

Referring to these figures, A and B represent main power lines, while Aand B represent branch power lines leading to the load. 'Ihe relay isapplicable to the lines A and B' to indicate a grounded condition ineither between it and the load, and also to indicate which line isgrounded. Furthermore, it functions only in such instances, and remainsinoperative when a ground occurs between it and the main power supplylines A and B. In addition, the relay functions even though none of thepower lines are normally grounded.

The relay includes the combination of a solenoid I which is connected inseries with the line A', a solenoid 2 which is connected in series withthe line B', a solenoid 3 arrange'd to magnetically oppose the solenoidI and having one end connected to the load end of the solenoid 2, asolenoid 4 arranged to magnetically oppose the solenoid 2 and having oneend connected to the load end of the solenoid I, the other ends of thesolenoids 3 and 4 being interconnected arranged to magnetically opposethe solenoid 2 and connected in series with the solenoids I and 3, aground connected between the solenoids 3 and 4, and a circuit closingmeans responsive to the relative magnetic forces of the solenoids I and2 as respectively modified by the solenoids 3 and 4.

The above named means includes the combination of an armature 5associated with the solenoids I and 3, an armature 6 associated with the'solenoids 2 and 4, a balancing beam I interconnecting the armatures 5and v6, adjustable means 8 for urging the beam I to balancing position,and contacts 9 operable by movement of the beam 1.

To aid in describing the operation of the relay, the connection betweenthe solenoids 3 and 2 is numbered III, that between the solenoids 3 and4 is numbered II, and that between the `solenoids 4 and I is numberedI2, while the connection from the ground I3 to the connection II betweenthe solenoids'3 and 4 is numbered |35.

All of the solenoids have substantially the same electrical and magneticcharacteristics, while the connections I0 and I2, and the branches ofthe connection II between the connection I3* and the solenoids 3 and 4,respectively provide substantially the same electrical resistances.

When there is no ground in any of the lines the current flows from theline A through the line A', the solenoid I and the load, and returns tothe line B by way of the line B and the solenoid 2. Since the solenoidsI and 2 exert equal forces, the armatures 5 and 6 will pull equalamounts, and the beam 'I remains in balance.

If a ground occurs at any point in the lines A and B, or in the lines A'and B between the relay and the lines A and B, the relay will remaininoperative. As an example, let it be assumed that a ground occurs atthe point Y. This will place this point and the ground I3 at the samepotential, the ground circuit being considered as having no appreciableresistance. Then the current which will ilow from the ground I3 to theline B by way of the line B', will go through the connection II andsolenoids 3 and 2. It follows that the solenoids 3 and 2 willrespectively pull the armatures 5 and 6 equal amounts so that the beam 1remains in balance and the relay does not operate. Furthermore, it isapparent that the same results cannot be obtained without the solenoidsI and 2. That is to say, if only the solenoids 3 and 4 are used a groundat the point Y will energize the solenoid 3 and result in operation ofthe relay because the solenoid 4 will not be energized to produce abalance.

However, if the ground occurs in any part of the lines A and B betweenthe relay and the load, the relay will not only operate but willindicate in which of these lines the ground occurs. As an example ofthis operation, let it be assumed that a ground occurs in the line A' atthe point X. 'I'hen the point X and the ground I3 will be placed in thesame potential and the current will flow from the line A by way of theline A' through the solenoid I to the point X, from there to the groundI3 and through the connection I3- to the solenoid 3, and from there tothe line B by way of the line B and solenoids 3 and 2.A The solenoid 3opposes the solenoid I so that the magnetic force of the former isneutralized. However, the solenoid 4 is not energized, and the solenoid2 can consequently exert a pull on the armature 6 which causes the beam'I to be moved so that operation of the contacts 9 is eifected. If theground had occurred in the line B between the relay and the load theoperation would have been the same except that the beam 1 would swing inthe opposite direction. Assuming the contacts 9 include a movablecontact which is moved to one or another oi two fixed contacts, it isobviously possible to effect the closing of one or another of twocircuits upon such grounding of one or another of the lines A' and B'.Thus the relay is selectively operated by such. grounding.

Referring to Figure 2, the solenoids I and 2 are illustrated as beingsplit into three sections, while the solenoids 3 and 4 are likewisesplit into three sections, the respective sections of the solenoids Iand 3, and 2 and 4 being alternately arranged one above another inconcentric relationship. The armatures 5 and 6 are both freely suspendedfrom the balancing beam 1, while the adjustable means 8 consists ofsensitive springs 8 provided with tension adjusting screw members 8b.Since the power carried by the lines A and B' will often be too large tobe accommodated practically by the various solenoids, resistances I4 areillustrated as shunting the major portion of the current around thesolenoids I and 2, While a resistance I5 is placed in the connectionII.. The ground connection I i!a should then connect into thisresistance I5 at a midpoint, or at such a point as is necessary to eiecta properly balanced arrangement. The contacts 9 are not specificallydescribed for the reason that they may follow conventional practice.

-I claim: 1. A relay that is selectively responsive to grounding ofeither of two power lines and which includes the combination of a firstsolenoid adapted to be connected in series with one of said lines, asecond solenoid adapted Pto be connected in series with the other ofsaid lines, a third solenoid arranged to magnetically oppose said iirstsolenoid and having one end connected to the load end of said secondsolenoid, a fourth solenoid arranged to magneticallyoppose said secondsolenoid and having one end connected to the load end of said firstsolenoid, the other ends of said third and fourth solenoids beinginterconnected, a ground connected between said third and fourthsolenoids, and circuit closing means responsive to the relative magneticforces of said first and second solenoids as respectively modified bysaid third and fourth solenoids.

2. A relay that is selectively responsive to grounding of either of twopower lines and which includes the combination of a rst solenoid adaptedto be connected in series with one of said lines, a second solenoidadapted to be connected in series with the other of said lines, a thirdsolenoid arranged to magnetically oppose said first solenoid and havingone end connected to the load end of said second solenoid, a fourthsolenoid arranged to magnetically oppose said second solenoid and havingone end connected to the load end of said iirst solenoid, the other endsof said third and fourth solenoids being interconnected, a groundconnected between said third and fourth solenoids, a rst armatureassociated with said first and third solenoids, a second armatureassociated with said second and fourth solenoids, a balancing beaminterconnecting said first and second armatures, adjustable means forurging said beam to balancing position and contacts operable by movementof said beam.

3. A relay that is selectively responsive to grounding of either of twopower lines and which includes the combination of a first solenoidadapted to be connected in series with one of said lines, a secondsolenoid adapted to be connected in series with the other of said lines,a third solenoid arranged to magnetically oppose said rst solenoidl andhaving one end connected to the load end of said second solenoid, afourth solenoid arranged to magnetically oppose said second solenoid andhaving one end connected to the load end of said rst solenoid, the otherends of said third and fourth solenoids being interconnected, a groundconnected between said third and fourth solenoids, a rst armatureassociated with said first and third solenoids, a second armatureassociated with said second and fourth solenoids, a balancing beaminterconnecting said first and second armatures, and contactsoperable bymovement of said beam, all of said solenoids having substantially thebeing so associated that the electrical resistances from said ground tosaid third and fourth solenoids are substantially the same and so thatthe electrical resistances fromsaid third solenoid to said secondsolenoid and from said fourth solenoid to said first solenoid aresubstantially equal.

HERBERT LEON COE.

.40 same electrical and magnetic characteristics and

